Nuclear issues and analysis for ARIES spherical and advanced tokamaks

During the past few years, the ARIES team has developed advanced designs to identify the physics and technology areas of high leverage for achieving environmentally attractive and economically competitive fusion power plants. This paper documents the key neutronics parameters and identifies the nuclear issues for the most recent spherical and advanced tokamak designs. The nuclear assessment played an important role during the design process. For instance, the excessive radiation damage to the resistive magnet of the spherical tokamak design provided strong incentives to shield the center post in order to prolong its lifetime and enhance the overall power balance. At present, a number of advanced blanket concepts based on the SiC/SiC composites are being investigated for the advanced tokamak study. An assessment of the breeding performance of the candidate breeders (LiPb, LiSn, and FLiBe) was conducted. The design implications are discussed along with issues related to the limited breeding potential of the LiSn and FLiBe breeders.